The broad objective of this Shared Facility is to make peptide sequencing using Edman chemistry and peptide synthesis services, as well as amino acid composition analysis, readily available to Cancer Center researchers. Identification of an isolated protein, whether a previously described or previously unreported protein, is an essential part of many research projects and commonly is best achieved by N-terminal sequencing. The design of oligonucleotide probes for molecular biological studies is most often based upon limited peptide sequence obtained from N-terminal sequence analysis. There are many needs for synthesis of peptides: frequently to be conjugated to protein and used as specific immunogens. The Cancer Center's Shared Facility for Peptide Analysis & Synthesis sequences 150-250 peptides and synthesizes 90-120 peptides annually. More than 70% of these services are for Cancer Center faculty. The present extent of usage of the Facility is indicative of the need for and value of these services. Their importance in helping to achieve the goals of many Cancer Center research projects is outlined elsewhere in this renewal proposal. Recently, methodologies for obtaining internal N-terminal sequence of peptides derived from proteins electroblotted to PVDF have been established and made available in this Facility. Also, the Facility' web page has been enhanced and now includes full descriptions of services offered and methodologies to be employed. The methodologies used by the Facility have matured and are no longer subject to rapid change. There is constant interaction with the Mass Spectrometry Shared Facility to ensure that the most appropriate and efficient techniques are recommended in each experimental situation. In addition, it is usual practice to utilize MALDI TOF MS analysis to verify the composition of peptides synthesized and to select the most desirable peptides for sequence analysis. It is predictable that MS will be used increasingly for many sequencing tasks.